Among the many validated HRGs, we decided to further analyze the contributions to tumor growth by VEGF, Cyclin D1 (CCND1), ENOLASE2 (ENO2), EGLN3, ANGPTL4, GLUT1, and IGFBP3, because they are involved in many well-known aspects of HIF biology but their roles were not directly investigated in a ccRCC xenograft model. This evidence concerns the gene IGFBP3 and neoplasm.